变频器安装使用前应重视的几个问题     

高丽洁 《长江工程职业技术学院学报》2004,21(3):24-25

选用变频器时功能并不是越多越复杂越好,只要按负载的特性,满足使用要求即可,并指出了安装环境对变频器影响及安装时的注意事项.  相似文献   

Emotion regulation and motor performance: an integrated review and proposal of the Temporal Influence Model of Emotion Regulation (TIMER)     

Garrett F. Beatty  Christopher M. Janelle 《International review of sport and exercise psychology》2020,13(1):266-296

ABSTRACT

Adaptive regulation of emotions is imperative for successful sport performance. However, the lion’s share of mainstream emotion regulation (ER) literature is founded on perspectives prioritising mental health, not performance. Consequently, ER strategies are predominantly classified as adaptive or maladaptive based on effectiveness in achieving targeted mental health outcomes. These conventional mental health classifications can catalyse misapplication of ER strategies within sport and other motor performance contexts when (1) ER motives are instrumentally directed towards performance enhancement and (2) Minimal consideration is given to the consequences of ER on the coordination and execution of motor actions. Herein, we review the current state of relevant ER research within and outside of sport contexts. We also present a novel conceptual framework, the Temporal Influence Model of Emotion Regulation (TIMER). TIMER proposes that ER strategies exert distinct, temporally dependent demands upon perceptual-cognitive and motoric resources. These unique regulatory profiles influence subsequent motor performance outcomes. Critically, the degree to which regulatory strategies are appropriate or ideal varies given environmental constraints along with performers’ affective and performance goals. The model includes testable hypotheses to guide theoretical and applied research in the domain of ER within sport and other motor performance contexts.  相似文献   

The kinematic differences between accurate and inaccurate squash forehand drives for athletes of different skill levels     

Benjamin K. Williams  Ross H. Sanders  Joong Hyun Ryu  Philip Graham-Smith  Peter J. Sinclair 《Journal of sports sciences》2020,38(10):1115-1123

ABSTRACT

To maintain the accuracy of squash shots under varying conditions, such as the oncoming ball’s velocity and trajectory, players must adjust their technique. Although differences in technique between skilled and less-skilled players have been studied, it is not yet understood how players vary their technique in a functional manner to maintain accuracy under varying conditions. This study compared 3-dimensional joint and racket kinematics and their variability between accurate and inaccurate squash forehand drives of 9 highly skilled and 9 less-skilled male athletes. During inaccurate shots, less-skilled players hit the ball with a more open racket, demonstrating a difference in this task-relevant parameter. No joint kinematic differences were found for accuracy for either group. Coordinated joint rotations at the elbow and wrist both displayed a “zeroing-in” effect, whereby movement variability was reduced from the initiation of propulsive joint rotation to a higher consistency at ball-impact; potentially highlighting the “functionality” of the variability prior to the impact that enabled consistent task-relevant parameters (racket orientation and velocity) under varying conditions. Further, highly skilled players demonstrated greater consistency of task-relevant parameters at impact than less-skilled players. These findings highlight the superior ability of highly skilled players to adjust their technique to achieve consistent task-relevant parameters and a successful shot.  相似文献   

动作发展视域下幼儿足球促进粗大动作发展水平研究     

孙启成  刘金富  朱小烽 《浙江体育科学》2020,(3):57-63

探讨幼儿足球对幼儿粗大动作发展水平的影响,为干预幼儿粗大动作发展提供依据。选取嘉兴市108名5~6岁幼儿为受试对象,以班级为单位随机分为干预组与对照组。干预组进行12周幼儿足球游戏活动教学,2次*40min/周;对照组幼儿为静态性的课堂班级活动。干预前后采用PGMQS测量幼儿位移能力、操控能力及平衡能力。采用独立样本t检验、配对样本t检验及协方差分析两组幼儿前后测结果的差异性。结果显示:①干预前,两组幼儿粗大动作发展水平无显著性差异(P>0.05);干预后,两组幼儿粗大动作发展水平存在显著性差异(P<0.05),干预组高于对照组。②干预组和对照组幼儿后测结果与前测结果间均存在显著性差异(P<0.05),后测结果高于前测。研究结果表明幼儿粗大动作发展存在延长效应,但结构化幼儿足球游戏活动明显提高了幼儿粗大动作发展水平。因此建议抓牢幼儿早期动作发展的敏感期,以动作发展为主线科学设计幼儿足球游戏活动并保证活动的顺利开展,为幼儿健康、全面发展奠定良好的基础。  相似文献   

电机及电力拖动实验教学方式改革探索     

李焦明 《广东白云职业技术学院广州白云工商高级技工学校学报》2007,14(1):78-80

针对实验教学目标的能力定位,对电机及电力拖动实验教学方式进行了改革,突出了实验技能和工程问题分析能力的培养。  相似文献   

交流异步电机状态变量观测及其优化控制     

廖育武 《襄樊学院学报》2002,23(2):62-64

采用维持磁通始终恒定的方法对电机转矩直接控制，可解决交流异步电机控制精度和系统复杂性之间的矛盾，在电机状态变量观测及位置控制中应用了现代控制理论，和传统的矢量控制方法相比，在相同的性能指标下，该系统便于用微机来完成实时控制。  相似文献   

家用型混合动力汽车电机动力匹配分析     

李敏旭  钟勇  江吉彬 《福建工程学院学报》2008,6(3):283-286

针对永磁同步电机对家用HEV的动力匹配、动力控制的工况匹配2个问题,建立合理的电机动力的数学模型.通过参数的取定和试验界定,计算分析了选用电机参数,实现了对车辆动力因素的匹配;同时分析了弱磁工况下实现电机动力控制匹配的相关问题.  相似文献   

混合动力汽车电机控制模型的仿真建立     

李敏旭  汤宁平 《福建工程学院学报》2008,6(Z1)

通过分析混合动力汽车电机控制的方法,设计永磁同步电机的直接转矩控制系统;建立相应的数学控制模型,并对相关的因素进行分析;通过具体的系统设计,获得相应的仿真结论.  相似文献   

微型直流电动机驱动试验分析     

詹良材 《鄂州大学学报》2008,15(2):37-40

该文论述了微型直流电动机驱动电路的基本原理．分析了以51单片机控制微型直流电动机正反转和调速的驱动电路．文中给出了具体的试验电路和试验结果。  相似文献   

屏幕背后：同步网络课堂教学效果影响因素研究     

李英明  叶海云  徐光涛 《教育技术导刊》2021,19(12):266-270

同步网络课堂（SCC）为边远地区学校输送了优秀的教学资源,成为近年来现代远程教育应用的一种重要形式。采用扎根理论和内容分析法,对影响较大的网络新闻和社交媒体上的49篇文章和1 236条有效评论进行系统分析,以寻找影响SCC教学效果的关键因素,并制定相应措施。结果表明,影响SCC教学有效性的关键因素包括6个主范畴及其25个子范畴,以及各因素之间存在的相互关系。最后,探索性地构建SCC教学有效性影响因素作用机制模型,并提出针对性和系统性的策略方案和实施路径,切实提升SCC教学效果。  相似文献